20 POLYPODIACEAE 



7. ADIANTTTM L. 



Delicate or graceful plants of rocky situations. Leaves 

 erect or pendulous, single or tufted on the rootstocks, 

 the petiole and its divisions black or dark, often shining: 

 blades pinnately or pedately compound, the leaflets 

 sometimes prominently jointed to the rachis, the midrib 

 wanting or marginal, veins mostly flabellate-forking, 

 free. Sori short, appearing marginal on the back of 

 the leaflets, borne at the ends of the veins. Indusia 

 formed by the more or less altered and reflexed lobes 

 of the leaflets. About one hundred and seventy-five 

 species, most abundant in tropical America. 



1. A. tenerum Sw. Eootstoek stout, creeping: leaves 

 erect, several together, mostly 1 m. long or less; petioles 

 often about as long as 

 the blade, but sometimes 

 shorter or sometimes 

 longer, polished ; blades 

 deltoid or ovate-deltoid 

 in outline, thrice-pinnate 

 or four-times pinnate, the 

 primary divisions long- 

 stalked; leaflets very 

 numerous, the blades ir- 

 regularly cuneate, mostly 

 1-2 cm. long, with fine 

 veins, slender-stalked, 

 prominently jointed at 

 the base: indusia scarcely 

 emarginate. (MAIDEN- 

 HAIR- FERN.) Hammocks. 

 Figure 11, reduced. 



This maidenhair-fern 

 reaches its best develop- 

 ment in the very dense 

 hammocks of the Bis- 

 cayne and Long Key pinelands, with much eroded floors. 



